The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

Bizarre lunar-like landscape with thousands of large stone "hoodoos."

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

A silly medieval mural preserved on the side of a Viennese house.

Op-art architecture designed for happiness.

This Austrian museum celebrates the work of famous forgers and their inimitable imitations.

Sparkling, calcite-covered skeletons of children who may have been sacrificed to appease an angry god.

The youngest volcano in Central America.

Hidden deep in the Guatemalan jungle is a turquoise paradise of natural pools, caves, and waterfalls.

Central America's deepest lake is actually a volcanic caldera, surrounded by three volcanoes.

This Slovak bridge is known both for its connection to a national uprising and its UFO-shaped eatery.

No need to strap in for a "ride" on this walkable roller coaster.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

A castle from the Holy Roman Empire that hosts traveling youth... in its stables.

Fantastic views and thousands of love locks.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

Late at night, the bust of the "Dracula" actor was snuck onto the facade of this Budapest castle.

Possibly the world's largest hourglass only needs to be reset every New Year's Eve.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.